Process of treating petroleum oil to produce low boiling point oil



Dec. 8, 1931. M. L, CHAPPELL PROCESS OF TREATING PETROLEUM OIL TO PRODUCE LOW BOILING POINT OIL Filed Sept.

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kumzm-oze@ gwmo@ 972mm@ g1g/@WM Patented Dec. 8, 1931 UNITED STATES PATENT OFFICE MARVIN L. CHAPPELL, OF LOS ANGELES, CALIFORNIA, ASSIG-NOR T0 STANDARD OIL COMPANY OF CALIFORNIA, OF

DELAWARE PROCESS OF TREATING PETROLEUM OIL TO PROD'GE LOW BOJIHTG POIN'TOIL Application led September 16, 1926. Serial N0. 135,845.

possess a highsulphur content, which sul-v phur content is extremely diicult to remove from the cracked naphtha.

There are also a :number of different hydrocarbon oils, which, due either'to their high sulphur content or their high content of unsaturated materials, cannot be profitably cracked by a pressure cracking system to produce low boiling point materials. For example, the high boiling' point materials delrived from the cracking process, such as the steam still bottoms, contain a large percentage of unsaturated constituents, and accordingly, if such oils are directly heated under temperature andpressure to decompose the oils into lower boiling point oils, they rapidly carbonize and give a very low yield. This is particularly true of such oils when they have been derived from an asphaltic or California base crude. Also such oils as are obtained in a sulphur dioxide extract of petroleum oils are substantially unsaturated materials and aromatic materials, and give very high losses if the same are directly subjected to heat and pressure in order to decompose the same into low boiling point materials. Y

It is the object of the present invention to provide a process for producing low boiling point oils or naphtha from petroleum oils or hydrocarbons, which is adapted to both substantially reduce the sulphur content of the oils and substantially eliminate the unsat- V urated constituents of the oils before they are subjected' to a cracking operation under heat and pressure, with the result that many oils, such as high sulphur bearing oils or oils containing a high percentage ofv unsaturated materials, may be cracked with-a materially higher yield and produce a materially superior product. y

In accordance with the present invention, an oil containing a substantial percentage of unsaturated materials or containing a substantial ercentage of sulphur or both is Erst subjected to treatment with a lmetallic halide, such asv aluminum chloride 'or zinc chloride, iron chloride, etc., under conditions to effect mainly a polymerization of the unsaturated constituents into saturated constituents and to remove the larger portion of the sulphur. constituents of the oil. The stock thus treated is then subjected to the requisite temperature and pressure to decompose said oil to form a low boiling point oil or naphtha. The process of the present invention is preferably a continuous process.

The present linvention also results in a novel form of low boiling point oil or naphtha. which is to be digingmshed lfrom the prior oils of this character, in that it combines high SAN FRANCISCO, CALIFORNIA, A OORPORATION OF nondetonating properties together with a cyclic compounds and by a temperature and pressure cracking or decomposing reaction in which unsaturated materials are produced therefrom, possesses non-detonating properties superior to that produced either vfrom a straight cracking operation or from a normal aluminum chloride process, and also possesses an unusually low sulphur content.

' Various `further objects and advantages of the present invention will be apparent from the description of a preferred form or example of a process embodying the invention. For this purpose, reference is made to the accompanying drawings, in which thereV is illustrated-a form of apparatus in which the process of the present mvention may be performed.

The drawings represent a diagrammaticv View of the apparatus, -in which the parts are mainly in vertical section.

Referring tothe drawings, the preferred continuous process is performed bypassing the fresh oil to be treated from line 2 by means of a pump 6 through a pre-heater 3 to line 4 1nto an aluminum chloride reaction chamber 5. The process is described referring to aluminum chloride, Which is to be regarded as merely an example of a metallic halide as other metallic halides may be employed. The oil to be treated may be any hydrocarbon oil, Whether derivedfrom shale,coal or petroleum, but the process is particularly valuable for the treatment of such oil as is either high in sulphur or high in unsaturated constituents. Preferably the oil is heated in the pre-heater 3 to substantially the reaction temperature desired in reaction chamber 5. Said temperature will depend largely upon the character of oil supplied to the system and the percentage of aluminum chloride provided for reacting therewith, also upon whether it is desired to produce a material percentage of naphtha from the aluminum chloride reaction. When it is desired to produce substantially only polymerized stock, the temperature will normally range from O F. to 450o F., and usually around 300O F. In certain cases it may be desirable to produce a substantial percentage of naptha from aluminum chloride reaction as well as to polymerize the remainder of the stock, and in this case temperatures as high as 600O F. or higher may be employed. I generally prefer, in operating upon an oil high in sulphur content, to permit at least some conversion of the oil into the low boiling point naphtha in reaction chamber 5, in order to more efliciently remove therefrom the sulphur bearing constituents.

The reaction chamber 5 is preferably a horizontal cylindrical chamber provided With a shaft 7, and mounted within the chamber is a paddle or scraper 8 to provide a means for agitating tarry residue which will collect Within the chamber. When it is desired to operate the process continuously, the chamber is preferably provided with a baie 9 forming at one end of the chamber a separating compartment 10 wherein the oil and tar can settle so the said constituents may be continuously or intermittently withdrawn from the reaction chamber 5 so that said reaction chamber 5 may be continuously operated. The reaction chamber 5 is also indicated as preferably mounted over furnace 11, provided with a burner 12, or other suitable heating means, so that when desired further heat may be supplied to the materials within reaction chamber 5 to maintain the desired reaction temperature, although in certain cases no heat may be supplied to said chamber, and reliance placed solely on the heat of the incoming oil from the pre-heater 3.

The reaction chamber 5 is also indicated as connecting through an inlet 13 having a valve 14 With a charging chamber 15. Said charging chamber 15 is in turn connected with a line 16 which may lead to a source of anhydrous aluminum chloride. .The aluminum chloride may be made liquid by mixing With suthcient oil, as is the usual practice. In the operation of the process, anhydrous aluminum chloride is continuously or intermittently fed from line 16 through charger 15 and inlet 13 into reaction chamber 5. The charger 15 is provided for use Where the reaction in chamber 5 is intended to be operated under pressure.

The process of the present invention may be operated either With or Without a pressure above atmospheric. Vhere pressure above atmospheric is employed, the anhydrous aluminum chloride is intermittently fed into the reaction chamber 5 by first closing the valve 14, placing a desired quantity of aluminum chloride in charger 15, then closing valve on line 16 and opening valve 14 to empty the charge Iinto the reaction chamber.

The quantity of aluminum chloride to be employed will also depend upon the character of oil fed into the reaction chamber, the temperature employed in the reaction chamber, and the amount of naphtha, if any, which it is desired to produce Within said chamber. Normally this percentage will vary from between .5% and 10% aluminum chloride by weight. In certain cases it is desirable to add in the reaction chamber 5 considerable excess aluminum chloride over that necessary for the'desired polymerizing reaction, and limit the reaction mainly to a polymerizing reaction by the employment of low temperatures, in which case the partly spent aluminum chloride residue in reaction chamber 5 may be later employed in other aluminum chloride conversion processes. A small amount of aluminum chloride may be employed in the reaction chamber Where high temperatures are desirable, and thereby the reaction can be limited mainly to a polymerizing action.

In any case the aluminum chloride and oil are continuously agitated together Within the reaction chamber 5 with the result that an aluminum chloride tar or residue is continuously formed, which settles within the lower portion of compartment 10 and is therefrom withdrawn to the residual line 17 either continuously or intermittently. "Where the reaction in chamber 5 is controlled solely to polymerize the oil stock, said polymerized oil stock is continuously Withdrawn from the upper portion of compartment 10 through line 18 by pump 19, and then continuously conducted into the pressure cracking portion of the apparatus. The line 18 is preferably provided with a trap 20, in which may be separated any aluminum chloride residuum which might be entrained in the polymerized oil passing through said line. Normally the operation will result Iin the production of at least some naphtha, in which case said naphtha is preferably continuously vaporized from the oil within reaction chamber 5, and.

passed through the vapor line 21 into a dephlegmator 22, wherein the heavy polymerized stock may be separated from the produced naphtha, and wherein any entrained aluminum chloride may also be separate.

The dephlegmator 22 is indicated as provided at its upper portion with a planer 23 through which a cooling medium may-be passed from line 24 and 25 to effect the desired reiuxing and control the temperature of the discharged vapors. The discharged naphtha vaporsare preferably passed through line 26 and condenser 27 1nt o a naphtha receiver 28. The 4naphtha receiver 28 is indicated as provided with a valved gas voutlet 29 and a pressure gauge 30 by which the pressure applied to the system may be controlled.

At the bottom of the dephlegmator there is provided a settling space for polymerized oil and aluminum chloride condensed from the vapors within said dephlegmator. Any aluminum chloride settled may be continuously passed through a return line 31 and back again into the reaction chamber 5 together with said polymerized oil, but preferably the polymerized oil fis withdrawn through line 32 and passed together with other polymerized oil from line 18 into the pressure cracking apparatus of the process. In certain cases it may be desirable to vaporize all of the polymerized oil and later collect the same in the dephlegmator 22, and pass all t-he polymerized oil therefrom to the pressure cracking apparatus, in place of withdrawing any of said oil through the line 18.

The reaction chamber 5 may be operated at atmospheric pressure or below atmospheric pressure, but I generally prefer to employ a pressure above atmospheric, such as from 15 to 50 pounds per square inch or greater. Said pressure permits a higher temperature to be employedwithin the reaction chamber 5, and consequently more eflicient utilization of aluminum chloride, and also facilitates the clean separation of the produced naphtha from polymer-ized oil, which is desired toxbe charged to the pressure cracking portioni' of the apparatus.

The oil withdrawn by pump 19 is substantially free ofunsaturated constituents and contains a large percentage of cyclic compounds and an extremely -low percentage of sulphur, and constitutes an exceptionally desirable charging stock for a pressure cracking plant.v Said oil is then subjected to the requisite temperature of cracking to cause said oil to decompose and form low boiling point oil or naphtha. This portion of the process may be performed in a great variety of ways.

F. and 900 F. From the heating coil 32a the oil is passed through a line 34 into a reaction chamber 35. Within the reaction chamber 35 the oil is held under pressure suitable to maintain the same in the liquid state until the cracking or decomposition reaction is complete. The pressure generally ranges from 80 pounds to 300 pounds per square inch, although higher pressures may be employed. The produced naphtha is continuously vapor ized from the reaction chamber 35 and passed through vapor line 36 to a dephlegmator 37. The oil within the reaction chamber 35 may be reduced to naphtha and a tarry residue which may be continuously withdrawn from the line 38, or the oil may be reduced to naphtha and coke. ln case it is intended to form coke within reaction chamb r 35, the chamber is preferably provided w' h suitable means, such as a wirecable 39, by which said coke may bewithdrawn therefrom.

The naphtha vapors passing into dephlegmator 37 are therein separated from any nondecomposed oil, which is preferably returned through reflex line 40 back to the stream of fresh polymerized oil being passed into the heating coil 32a. The dephlegmator 37 is indlcated as preferably provided with a planer 41 as a suitable temperature control means.

The cracked naphtha is passed from dephlegmator 37 through line 42 and condensed 1n condenser 43 and discharged into the naphtha receiver 44. Said naphtha receiver 1s indicated as provided with a gas outlet line 45 having a valve 46 with a gauge 47. B'y said `means the pressure throughout the pressure decomposition apparatus may be controlled.

The. pressure naphtha produced in accord` ance wit-h the process of the present invention possesses less sulphur compounds than pressure naphtha produced in other pressure crackling processes, and moreover is composed of ingredients derived through both a polymerization and pressure decomposition reaction, so that the naphtha is of different character than that ordinarily derived from petroleum oil, either by straight distillation aluminum chloride treatment or pressure distillation, and is superior in non-detonating properties to normal naphtha.

The important feature or advantage of the process of the present invention is the ability to successfully process oils containing a high percentage of unsaturated materials. For example, at the present time the oils extracted from petroleum oil by sulphur dioxide in difly decompose or crack said oil and form low ferent purification processes have at present boiling point oil. no value except as fuel oil. The present in- Singned at San Francisco this 28th day of vention permits said oils to be readily poly- August, 1926. i

5 merized and then cracked into a high grade MARVIN L. CHAPPELL. 70

naphtha.

While the particular process herein described is Well adapted to carry out the obliects of the present invention, various modifications and changes may be made without departing from the spirit of the invention. The invention includes all such modifications and changes as come Within the scope of the appended claims.

I claim z- 80 1. A process of producing lov:r boiling point oil or naphtha from oil recovered from a sulphur dioxide extract of a hydrocarbon oil` Which comprises heating and contacting such oil with an anhydrous aluminum chloride under conditions to polymerize a part of said oil, separating the polymerized oil from the aluminum chloride tar and then subjecting the polymerized oil to the requisite temperature and pressure to decom- 9o pose the oil or crack it to form low boiling point oil or naphtha.

2. A process of converting hydrocarbon oil into naphtha which comprises heating and subjecting said oil to reaction With anhydrous metallic halide, to polymerize a part of said oil and to decompose a part of said oil into naphtha, simultaneously vaporizing from the material undergoing treatment a lo "5 mixture of polymerized oil and naphtha, o

passing said mixture into a reiiux Zone Wherein said naphtha is separated from said polymerized oil and said polymerized oil is condensed, passing said polymerized oil con- 105 taining no metallic halides from said reiux zone through a pressure cracking chamber and therein subjecting said oil to the requisite temperature and pressure..

to thermallv decompose or crack said oil to form additional naph'tha. no

3. A process of producing low boiling point material from a hydrocarbon oil which comprises continuously heating the oil and passing the same into a reaction zone, therein n 5 continuously subjecting said oil to reaction with an anhydrous metallic halide, to polymerize a part of said oil and to decompose a part of said oil to form naphtha, continuously vaporizing said naphtha together with 120 a part of said polymerized oil, and passing the same through a reflux zone, continuously separating from said reflux zone said naphtha from said polymerized oil and continuously 60 passing said polymerized oil containing no 125 metallic halides from said reflux zone together With polymerized oil from said reaction zone into a cracking zone, and therein continuously subjecting said oil to the req- 65 uisite temperature and pressure to thermal- W0 

